1. Field of the Invention
The present invention relates to the preparation and regeneration of drilling mud. More particularly, the invention relates to a method of monitoring structural and mechanical properties of drilling mud and a device for realizing same.
The present invention can be most advantageously used in petroleum and gas industries for preparation of mud.
This invention can also be successsfully employed for regeneration of mud, that is for regeneration of initial properties of mud.
2. Prior Art
At present, clay mud is extensively used in drilling holes of various depths.
Structural and mechanical properties of drilling mud based on clay are often characterized by the viscosity of mud, which is determined by rotary viscosimeters of various designs. Besides, such properties can be characterized by shear strength which can be found by means of laboratory methods.
Structural and mechanical properties of clay drilling mud are currently often defined by the so-called "coagulation index" (CI) which is in fact the ratio of the shear strength to the viscosity of mud. This index characterizes the degree of coagulation of mud.
In modern practice, both characteristics are measured manually and independently, that is, the viscosity is measured by viscosimeters of any type, whereas the shear strength is found by means of a special instrument for measuring the shear strength. Manual measurements are time consuming and irregular, so that accuracy is unavoidably impaired. This, as may be expected, permits no uninterrupted monitoring of mud condition in the process of preparation and during circulation in the hole, which are vital prerequisites of successful hole sinking.
This is also a disadvantage as far as automation of mud preparation is concerned.